Metal-dependent phase selection in coordination polymers derived from a C(2V)-symmetric tricarboxylate.

Reacting biphenyl-3,4',5-tricarboxylic acid (H(3)BHTC) with the appropriate metal salt yields the microporous coordination polymers (MCPs) Mn(3)(BHTC)(2) (1), Mg(3)(BHTC)(2) (2), and Co(3)(BHTC)(2) (3) containing hourglass metal clusters. The addition of Cu to reactions with Co(II), Fe(III), or Mn(II) leads to the formation of heterobimetallic UMCM-150 isostructural analogues Co(1)Cu(2)(BHTC)(2) (4), Fe(1)Cu(2)(BHTC)(2) (5), and Mn(1)Cu(2)(BHTC)(2) (6) containing both paddlewheel and trinuclear metal clusters. X-ray diffraction analysis of the crystals of the heterobimetallic MCPs suggests that Cu on the trinuclear site of UMCM-150 was replaced by the other metal, whereas Cu in paddlewheel sites remains unchanged. N(2) sorption isotherms were measured for the mixed-metal UMCM-150 analogues, and it was confirmed that there is no structural collapse after the metal replacement.